An accurate and fast in-out classification of a mobile device location is beneficial for many mobile device navigation applications. The in-out classification can classify the mobile device location as “in” or “out” of an indoor area by comparing a location determined, for example, by a global navigation satellite system (GNSS) (e.g., global positioning system (GPS)) with mapping information for the indoor area. The results of the in-out classification may determine a preferred location determination method. For example, GNSS based positioning may be preferred if the mobile device location is classified as “out” of the indoor area and Wi-Fi based positioning may be preferred if the mobile device location is classified as “in” the indoor area.